根据不同条件选择行

Question

My source table looks something like below

This is the intermediate step

And the final output should look like below

Basically first I need to SELECT the lowest Rank for a PERSONID , AddressID and PhoneType . If there are multiple rows with the same Rank , then I need to return which ever has the max VerificationDate and then get the final output.

Create statement:

CREATE TABLE AddressPhone ([PERSONID] [varchar](10) NOT NULL,
                           [AddressID] [int] NOT NULL,
                           [PhoneType] [varchar](2) NOT NULL,
                           [PhoneNumber] [varchar](15) NOT NULL,
                           [VerificationDate] [datetime] NOT NULL,
                           [Rank] [int] NOT NULL) ON [PRIMARY];

Answer 1

Try this query:

Sample data ( not the same, but it is equivalent ):

declare @tbl table (personid int, addressid int, phonetype bit, phonenumber int, verificationdate date, rank int);
insert into @tbl values
(1, 1, 0, null, '2014-06-24', 4),
(1, 1, 1, null, '2014-06-24', 4),
(1, 1, 1, null, '2014-06-24', 4),
(1, 1, 1, null, '2014-06-24', 4),
(1, 1, 1, null, '2014-06-24', 4),
(1, 1, 0, null, '2014-06-24', 4),
(1, 1, 0, null, '2014-06-24', 3),
(1, 1, 0, null, '2014-06-24', 4),
(1, 1, 1, null, '2014-06-24', 2),
(1, 1, 1, null, '2014-06-24', 1),
(1, 1, 0, null, '2014-06-24', 4),
(1, 1, 1, null, '2014-06-24', 4),

(2, 2, 0, null, '2014-06-24', 2),
(2, 2, 0, null, '2014-06-24', 1),
(2, 2, 0, null, '2014-06-24', 4),
(2, 2, 1, null, '2014-06-25', 1),
(2, 2, 1, null, '2014-06-24', 1);

--intermediate step
select personid, addressid, phonetype, phonenumber, verificationdate, rank,
       row_number() over (partition by rank order by verificationdate) rnVerDate
from (
    select personid, addressid, phonetype, phonenumber, verificationdate, rank,
           row_number() over (partition by personid, addressid, phonetype order by rank desc) rnRank
    from @tbl
) a where rnRank = 1

--final result
select personid, addressid, phonetype, phonenumber, verificationdate, rank
from (
    select personid, addressid, phonetype, phonenumber, verificationdate, rank,
           row_number() over (partition by rank order by verificationdate) rnVerDate
    from (
        select personid, addressid, phonetype, phonenumber, verificationdate, rank,
               row_number() over (partition by personid, addressid, phonetype order by rank desc) rnRank
        from @tbl
    ) a where rnRank = 1
) a where rnVerDate = 1